boost/proto/extends.hpp
/////////////////////////////////////////////////////////////////////////////// /// \file extends.hpp /// Macros and a base class for defining end-user expression types // // Copyright 2008 Eric Niebler. Distributed under the Boost // Software License, Version 1.0. (See accompanying file // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_PROTO_EXTENDS_HPP_EAN_11_1_2006 #define BOOST_PROTO_EXTENDS_HPP_EAN_11_1_2006 #include <cstddef> // for offsetof #include <boost/preprocessor/tuple/elem.hpp> #include <boost/preprocessor/control/if.hpp> #include <boost/preprocessor/arithmetic/inc.hpp> #include <boost/preprocessor/arithmetic/dec.hpp> #include <boost/preprocessor/iteration/local.hpp> #include <boost/preprocessor/repetition/enum_params.hpp> #include <boost/preprocessor/repetition/repeat_from_to.hpp> #include <boost/preprocessor/repetition/enum_binary_params.hpp> #include <boost/preprocessor/repetition/enum_trailing_params.hpp> #include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp> #include <boost/preprocessor/seq/for_each.hpp> #include <boost/utility/addressof.hpp> #include <boost/utility/result_of.hpp> #include <boost/proto/proto_fwd.hpp> #include <boost/proto/traits.hpp> #include <boost/proto/expr.hpp> #include <boost/proto/args.hpp> #include <boost/proto/traits.hpp> #include <boost/proto/generate.hpp> namespace boost { namespace proto { #ifdef __GNUC__ /// INTERNAL ONLY /// # define BOOST_PROTO_ADDROF(x) ((char const volatile*)boost::addressof(x)) /// INTERNAL ONLY /// # define BOOST_PROTO_OFFSETOF(s,m) (BOOST_PROTO_ADDROF((((s *)this)->m)) - BOOST_PROTO_ADDROF(*((s *)this))) #else /// INTERNAL ONLY /// # define BOOST_PROTO_OFFSETOF offsetof #endif /// INTERNAL ONLY /// #define BOOST_PROTO_CONST0 /// INTERNAL ONLY /// #define BOOST_PROTO_CONST1 const /// INTERNAL ONLY /// #define BOOST_PROTO_TEMPLATE_YES_(Z, N) template<BOOST_PP_ENUM_PARAMS_Z(Z, N, typename A)> /// INTERNAL ONLY /// #define BOOST_PROTO_TEMPLATE_NO_(Z, N) /// INTERNAL ONLY /// #define BOOST_PROTO_DEFINE_FUN_OP_IMPL_(Z, N, DATA, Const) \ BOOST_PP_IF(N, BOOST_PROTO_TEMPLATE_YES_, BOOST_PROTO_TEMPLATE_NO_)(Z, N) \ typename boost::result_of< \ proto_domain( \ typename boost::proto::result_of::BOOST_PP_CAT(funop, N)< \ proto_derived_expr BOOST_PROTO_CONST ## Const \ , proto_domain \ BOOST_PP_ENUM_TRAILING_PARAMS_Z(Z, N, const A) \ >::type \ ) \ >::type const \ operator ()(BOOST_PP_ENUM_BINARY_PARAMS_Z(Z, N, A, const &a)) BOOST_PROTO_CONST ## Const \ { \ typedef boost::proto::result_of::BOOST_PP_CAT(funop, N)< \ proto_derived_expr BOOST_PROTO_CONST ## Const \ , proto_domain \ BOOST_PP_ENUM_TRAILING_PARAMS_Z(Z, N, const A) \ > funop; \ return proto_domain()( \ funop::call( \ *static_cast<proto_derived_expr BOOST_PROTO_CONST ## Const *>(this) \ BOOST_PP_ENUM_TRAILING_PARAMS_Z(Z, N, a) \ ) \ ); \ } \ /**/ /// INTERNAL ONLY /// #define BOOST_PROTO_DEFINE_FUN_OP_VARIADIC_IMPL_(Const) \ template<typename... A> \ typename boost::result_of< \ proto_domain( \ typename boost::proto::result_of::funop< \ proto_derived_expr BOOST_PROTO_CONST ## Const(A const &...) \ , proto_derived_expr \ , proto_domain \ >::type \ ) \ >::type const \ operator ()(A const &...a) BOOST_PROTO_CONST ## Const \ { \ typedef boost::proto::result_of::funop< \ proto_derived_expr BOOST_PROTO_CONST ## Const(A const &...) \ , proto_derived_expr \ , proto_domain \ > funop; \ return proto_domain()( \ funop::call( \ *static_cast<proto_derived_expr BOOST_PROTO_CONST ## Const *>(this) \ , a... \ ) \ ); \ } \ /**/ /// INTERNAL ONLY /// #define BOOST_PROTO_DEFINE_FUN_OP_CONST(Z, N, DATA) \ BOOST_PROTO_DEFINE_FUN_OP_IMPL_(Z, N, DATA, 1) /// INTERNAL ONLY /// #define BOOST_PROTO_DEFINE_FUN_OP_NON_CONST(Z, N, DATA) \ BOOST_PROTO_DEFINE_FUN_OP_IMPL_(Z, N, DATA, 0) /// INTERNAL ONLY /// #define BOOST_PROTO_DEFINE_FUN_OP(Z, N, DATA) \ BOOST_PROTO_DEFINE_FUN_OP_CONST(Z, N, DATA) \ BOOST_PROTO_DEFINE_FUN_OP_NON_CONST(Z, N, DATA) \ /**/ /// INTERNAL ONLY /// #define BOOST_PROTO_EXTENDS_CHILD(Z, N, DATA) \ typedef \ typename proto_base_expr::BOOST_PP_CAT(proto_child, N) \ BOOST_PP_CAT(proto_child, N); \ /**/ #define BOOST_PROTO_BASIC_EXTENDS_(Expr, Derived, Domain) \ Expr proto_expr_; \ \ typedef Expr proto_base_expr_; /**< INTERNAL ONLY */ \ typedef typename proto_base_expr_::proto_base_expr proto_base_expr; \ typedef Domain proto_domain; \ typedef Derived proto_derived_expr; \ typedef typename proto_base_expr::proto_tag proto_tag; \ typedef typename proto_base_expr::proto_args proto_args; \ typedef typename proto_base_expr::proto_arity proto_arity; \ typedef typename proto_base_expr::address_of_hack_type_ proto_address_of_hack_type_; \ typedef void proto_is_expr_; /**< INTERNAL ONLY */ \ BOOST_STATIC_CONSTANT(long, proto_arity_c = proto_base_expr::proto_arity_c); \ typedef boost::proto::tag::proto_expr fusion_tag; \ BOOST_PP_REPEAT(BOOST_PROTO_MAX_ARITY, BOOST_PROTO_EXTENDS_CHILD, ~) \ \ static proto_derived_expr const make(Expr const &e) \ { \ proto_derived_expr that = {e}; \ return that; \ } \ \ proto_base_expr &proto_base() \ { \ return this->proto_expr_.proto_base(); \ } \ \ proto_base_expr const &proto_base() const \ { \ return this->proto_expr_.proto_base(); \ } \ \ operator proto_address_of_hack_type_() const \ { \ return boost::addressof(this->proto_base().child0); \ } \ /**/ #define BOOST_PROTO_BASIC_EXTENDS(Expr, Derived, Domain) \ BOOST_PROTO_BASIC_EXTENDS_(Expr, Derived, Domain) \ typedef void proto_is_aggregate_; \ /**< INTERNAL ONLY */ /// INTERNAL ONLY /// #define BOOST_PROTO_EXTENDS_ASSIGN_IMPL_(Const) \ template<typename A> \ typename boost::result_of< \ proto_domain( \ boost::proto::expr< \ boost::proto::tag::assign \ , boost::proto::list2< \ proto_derived_expr BOOST_PROTO_CONST ## Const & \ , typename boost::proto::result_of::as_child<A, proto_domain>::type \ > \ , 2 \ > \ ) \ >::type const \ operator =(A &a) BOOST_PROTO_CONST ## Const \ { \ typedef boost::proto::expr< \ boost::proto::tag::assign \ , boost::proto::list2< \ proto_derived_expr BOOST_PROTO_CONST ## Const & \ , typename boost::proto::result_of::as_child<A, proto_domain>::type \ > \ , 2 \ > that_type; \ that_type that = { \ *static_cast<proto_derived_expr BOOST_PROTO_CONST ## Const *>(this) \ , boost::proto::as_child<proto_domain>(a) \ }; \ return proto_domain()(that); \ } \ \ template<typename A> \ typename boost::result_of< \ proto_domain( \ boost::proto::expr< \ boost::proto::tag::assign \ , boost::proto::list2< \ proto_derived_expr BOOST_PROTO_CONST ## Const & \ , typename boost::proto::result_of::as_child<A const, proto_domain>::type \ > \ , 2 \ > \ ) \ >::type const \ operator =(A const &a) BOOST_PROTO_CONST ## Const \ { \ typedef boost::proto::expr< \ boost::proto::tag::assign \ , boost::proto::list2< \ proto_derived_expr BOOST_PROTO_CONST ## Const & \ , typename boost::proto::result_of::as_child<A const, proto_domain>::type \ > \ , 2 \ > that_type; \ that_type that = { \ *static_cast<proto_derived_expr BOOST_PROTO_CONST ## Const *>(this) \ , boost::proto::as_child<proto_domain>(a) \ }; \ return proto_domain()(that); \ } \ /**/ #define BOOST_PROTO_EXTENDS_ASSIGN_CONST() \ BOOST_PROTO_EXTENDS_ASSIGN_IMPL_(1) #define BOOST_PROTO_EXTENDS_ASSIGN_NON_CONST() \ BOOST_PROTO_EXTENDS_ASSIGN_IMPL_(0) #define BOOST_PROTO_EXTENDS_ASSIGN() \ BOOST_PROTO_EXTENDS_ASSIGN_CONST() \ BOOST_PROTO_EXTENDS_ASSIGN_NON_CONST() \ /**/ /// INTERNAL ONLY /// #define BOOST_PROTO_EXTENDS_SUBSCRIPT_IMPL_(Const) \ template<typename A> \ typename boost::result_of< \ proto_domain( \ boost::proto::expr< \ boost::proto::tag::subscript \ , boost::proto::list2< \ proto_derived_expr BOOST_PROTO_CONST ## Const & \ , typename boost::proto::result_of::as_child<A, proto_domain>::type \ > \ , 2 \ > \ ) \ >::type const \ operator [](A &a) BOOST_PROTO_CONST ## Const \ { \ typedef boost::proto::expr< \ boost::proto::tag::subscript \ , boost::proto::list2< \ proto_derived_expr BOOST_PROTO_CONST ## Const & \ , typename boost::proto::result_of::as_child<A, proto_domain>::type \ > \ , 2 \ > that_type; \ that_type that = { \ *static_cast<proto_derived_expr BOOST_PROTO_CONST ## Const *>(this) \ , boost::proto::as_child<proto_domain>(a) \ }; \ return proto_domain()(that); \ } \ \ template<typename A> \ typename boost::result_of< \ proto_domain( \ boost::proto::expr< \ boost::proto::tag::subscript \ , boost::proto::list2< \ proto_derived_expr BOOST_PROTO_CONST ## Const & \ , typename boost::proto::result_of::as_child<A const, proto_domain>::type \ > \ , 2 \ > \ ) \ >::type const \ operator [](A const &a) BOOST_PROTO_CONST ## Const \ { \ typedef boost::proto::expr< \ boost::proto::tag::subscript \ , boost::proto::list2< \ proto_derived_expr BOOST_PROTO_CONST ## Const & \ , typename boost::proto::result_of::as_child<A const, proto_domain>::type \ > \ , 2 \ > that_type; \ that_type that = { \ *static_cast<proto_derived_expr BOOST_PROTO_CONST ## Const *>(this) \ , boost::proto::as_child<proto_domain>(a) \ }; \ return proto_domain()(that); \ } \ /**/ #define BOOST_PROTO_EXTENDS_SUBSCRIPT_CONST() \ BOOST_PROTO_EXTENDS_SUBSCRIPT_IMPL_(1) #define BOOST_PROTO_EXTENDS_SUBSCRIPT_NON_CONST() \ BOOST_PROTO_EXTENDS_SUBSCRIPT_IMPL_(0) #define BOOST_PROTO_EXTENDS_SUBSCRIPT() \ BOOST_PROTO_EXTENDS_SUBSCRIPT_CONST() \ BOOST_PROTO_EXTENDS_SUBSCRIPT_NON_CONST() \ /**/ /// INTERNAL ONLY /// #define BOOST_PROTO_EXTENDS_FUNCTION_() \ template<typename Sig> \ struct result \ { \ typedef \ typename boost::result_of< \ proto_domain( \ typename boost::proto::result_of::funop< \ Sig \ , proto_derived_expr \ , proto_domain \ >::type \ ) \ >::type const \ type; \ }; \ /**/ #ifdef BOOST_HAS_VARIADIC_TMPL #define BOOST_PROTO_EXTENDS_FUNCTION_CONST() \ BOOST_PROTO_EXTENDS_FUNCTION_() \ BOOST_PROTO_DEFINE_FUN_OP_VARIADIC_IMPL_(1) \ /**/ #define BOOST_PROTO_EXTENDS_FUNCTION_NON_CONST() \ BOOST_PROTO_EXTENDS_FUNCTION_() \ BOOST_PROTO_DEFINE_FUN_OP_VARIADIC_IMPL_(0) \ /**/ #define BOOST_PROTO_EXTENDS_FUNCTION() \ BOOST_PROTO_EXTENDS_FUNCTION_() \ BOOST_PROTO_DEFINE_FUN_OP_VARIADIC_IMPL_(0) \ BOOST_PROTO_DEFINE_FUN_OP_VARIADIC_IMPL_(1) \ /**/ #else #define BOOST_PROTO_EXTENDS_FUNCTION_CONST() \ BOOST_PROTO_EXTENDS_FUNCTION_() \ BOOST_PP_REPEAT_FROM_TO( \ 0 \ , BOOST_PROTO_MAX_FUNCTION_CALL_ARITY \ , BOOST_PROTO_DEFINE_FUN_OP_CONST \ , ~ \ ) \ /**/ #define BOOST_PROTO_EXTENDS_FUNCTION_NON_CONST() \ BOOST_PROTO_EXTENDS_FUNCTION_() \ BOOST_PP_REPEAT_FROM_TO( \ 0 \ , BOOST_PROTO_MAX_FUNCTION_CALL_ARITY \ , BOOST_PROTO_DEFINE_FUN_OP_NON_CONST \ , ~ \ ) \ /**/ #define BOOST_PROTO_EXTENDS_FUNCTION() \ BOOST_PROTO_EXTENDS_FUNCTION_() \ BOOST_PP_REPEAT_FROM_TO( \ 0 \ , BOOST_PROTO_MAX_FUNCTION_CALL_ARITY \ , BOOST_PROTO_DEFINE_FUN_OP \ , ~ \ ) \ /**/ #endif #define BOOST_PROTO_EXTENDS(Expr, Derived, Domain) \ BOOST_PROTO_BASIC_EXTENDS(Expr, Derived, Domain) \ BOOST_PROTO_EXTENDS_ASSIGN() \ BOOST_PROTO_EXTENDS_SUBSCRIPT() \ BOOST_PROTO_EXTENDS_FUNCTION() \ /**/ namespace exprns_ { /// \brief Empty type to be used as a dummy template parameter of /// POD expression wrappers. It allows argument-dependent lookup /// to find Proto's operator overloads. /// /// \c proto::is_proto_expr allows argument-dependent lookup /// to find Proto's operator overloads. For example: /// /// \code /// template<typename T, typename Dummy = proto::is_proto_expr> /// struct my_terminal /// { /// BOOST_PROTO_BASIC_EXTENDS( /// typename proto::terminal<T>::type /// , my_terminal<T> /// , default_domain /// ) /// }; /// /// // ... /// my_terminal<int> _1, _2; /// _1 + _2; // OK, uses proto::operator+ /// \endcode /// /// Without the second \c Dummy template parameter, Proto's operator /// overloads would not be considered by name lookup. struct is_proto_expr {}; /// \brief extends\<\> class template for adding behaviors to a Proto expression template /// template< typename Expr , typename Derived , typename Domain // = proto::default_domain , long Arity // = Expr::proto_arity_c > struct extends { extends() : proto_expr_() {} extends(extends const &that) : proto_expr_(that.proto_expr_) {} extends(Expr const &expr_) : proto_expr_(expr_) {} BOOST_PROTO_BASIC_EXTENDS_(Expr, Derived, Domain) BOOST_PROTO_EXTENDS_ASSIGN_CONST() BOOST_PROTO_EXTENDS_SUBSCRIPT_CONST() // Instead of using BOOST_PROTO_EXTENDS_FUNCTION, which uses // nested preprocessor loops, use file iteration here to generate // the operator() overloads, which is more efficient. BOOST_PROTO_EXTENDS_FUNCTION_() #ifdef BOOST_HAS_VARIADIC_TMPL BOOST_PROTO_DEFINE_FUN_OP_VARIADIC_IMPL_(1) #else /// INTERNAL ONLY /// #define BOOST_PP_LOCAL_MACRO(N) \ BOOST_PROTO_DEFINE_FUN_OP_CONST(1, N, ~) \ /**/ /// INTERNAL ONLY /// #define BOOST_PP_LOCAL_LIMITS (0, BOOST_PP_DEC(BOOST_PROTO_MAX_FUNCTION_CALL_ARITY)) #include BOOST_PP_LOCAL_ITERATE() #endif }; /// \brief extends\<\> class template for adding behaviors to a Proto expression template /// template<typename Expr, typename Derived, typename Domain> struct extends<Expr, Derived, Domain, 0> { extends() : proto_expr_() {} extends(extends const &that) : proto_expr_(that.proto_expr_) {} extends(Expr const &expr_) : proto_expr_(expr_) {} BOOST_PROTO_BASIC_EXTENDS_(Expr, Derived, Domain) BOOST_PROTO_EXTENDS_ASSIGN() BOOST_PROTO_EXTENDS_SUBSCRIPT() // Instead of using BOOST_PROTO_EXTENDS_FUNCTION, which uses // nested preprocessor loops, use file iteration here to generate // the operator() overloads, which is more efficient. BOOST_PROTO_EXTENDS_FUNCTION_() #ifdef BOOST_HAS_VARIADIC_TMPL BOOST_PROTO_DEFINE_FUN_OP_VARIADIC_IMPL_(0) BOOST_PROTO_DEFINE_FUN_OP_VARIADIC_IMPL_(1) #else /// INTERNAL ONLY /// #define BOOST_PP_LOCAL_MACRO(N) \ BOOST_PROTO_DEFINE_FUN_OP(1, N, ~) \ /**/ /// INTERNAL ONLY /// #define BOOST_PP_LOCAL_LIMITS (0, BOOST_PP_DEC(BOOST_PROTO_MAX_FUNCTION_CALL_ARITY)) #include BOOST_PP_LOCAL_ITERATE() #endif }; /// INTERNAL ONLY /// template<typename This, typename Fun, typename Domain> struct virtual_member { typedef expr<tag::member, list2<This &, expr<tag::terminal, term<Fun> > const &>, 2> proto_base_expr; typedef Domain proto_domain; typedef virtual_member<This, Fun, Domain> proto_derived_expr; typedef typename proto_base_expr::proto_tag proto_tag; typedef typename proto_base_expr::proto_args proto_args; typedef typename proto_base_expr::proto_arity proto_arity; typedef typename proto_base_expr::address_of_hack_type_ proto_address_of_hack_type_; typedef void proto_is_expr_; /**< INTERNAL ONLY */ BOOST_STATIC_CONSTANT(long, proto_arity_c = proto_base_expr::proto_arity_c); typedef boost::proto::tag::proto_expr fusion_tag; BOOST_PP_REPEAT(BOOST_PROTO_MAX_ARITY, BOOST_PROTO_EXTENDS_CHILD, ~) typedef void proto_is_aggregate_; /**< INTERNAL ONLY */ BOOST_PROTO_EXTENDS_ASSIGN() BOOST_PROTO_EXTENDS_SUBSCRIPT() BOOST_PROTO_EXTENDS_FUNCTION() proto_base_expr const proto_base() const { proto_base_expr that = {this->child0(), this->child1()}; return that; } proto_child0 child0() const { return *(This *)((char *)this - BOOST_PROTO_OFFSETOF(This, proto_member_union_start_)); } proto_child1 child1() const { static expr<tag::terminal, term<Fun>, 0> const that = {Fun()}; return that; } }; /// INTERNAL ONLY /// #define BOOST_PROTO_EXTENDS_MEMBER_(R, DATA, ELEM) \ boost::proto::exprns_::virtual_member< \ proto_derived_expr \ , BOOST_PP_TUPLE_ELEM(2, 0, ELEM) \ , proto_domain \ > BOOST_PP_TUPLE_ELEM(2, 1, ELEM); \ /**/ /// \brief For declaring virtual data members in an extension class. /// #define BOOST_PROTO_EXTENDS_MEMBERS(SEQ) \ union \ { \ char proto_member_union_start_; \ BOOST_PP_SEQ_FOR_EACH(BOOST_PROTO_EXTENDS_MEMBER_, ~, SEQ) \ }; \ /**/ } }} #endif